Abstract: An object of the present invention is to provide a chain tensioner which enables operations on an elastic ring member during assembly and maintenance work to be readily performed and which is capable of eliminating protrusion of an operating portion of the elastic ring member in a direction opposite to a mounting surface, with a simple configuration. A ring holding portion 112 provided on an open side of a plunger housing hole 111 includes a pressing projection 113 and a restricting portion 114 which restrict rotation of the elastic ring member 130 and which oppose both outer sides of a pair of operating portions 132 of the elastic ring member 130 in a circumferential direction, and the pressing projection 113 is arranged at a position closer to a mounting surface 115 than the restricting portion 114.

Abstract: To provide a chain tensioner that has a simple structure, is universally usable and capable of supplying sufficient and necessary oil when restarted after a long time after the stop of oil supply, and enables reduction of its length and size. Urging unit 140 provided in an oil pressure chamber 101 to be extendable and contractible urges a plunger 120 outward from a plunger bore 111 in a tensioner body 110 of the chain tensioner 100. A connection groove 122 is formed in the outer circumference of the plunger 120 to form a supply chamber 102. An oil reservoir chamber 123 is formed inside the plunger 120. A leak groove 125 is formed in the outer circumference of the plunger 120 on the side of the oil pressure chamber 101 such as to extend into the supply chamber 102.

Abstract: Provided is a chain tensioner that is capable of restricting the movement of a plunger at an engagement position, hardly causes its breakage and abrasion even if receiving a great force applied to the plunger, needs no setting for a backlash amount, and allows the engagement position of the plunger to be freely shifted forward and backward. The tensioner body has an engagement member that extends toward and retracts from engagement grooves provided on the outer periphery of the plunger, a press member that presses, in one direction, a cam member which maintains and releases the extending state of the engagement member, and a hydraulic supply path through which oil is supplied to press the cam member in a direction opposite to the pressing direction of the press member.

Abstract: Provided is a chain tensioner that can, with a simple structure, supply sufficient and necessary oil when restarted after a long time after the stop of oil supply, and control pressing force in accordance with operating conditions during the drive, thereby reducing vibration of the chain not only when restarted but also during the drive. In a chain tensioner 100 in which a plunger 120 inserted in a plunger bore of a tensioner body 110 is biased outward by biasing means 140 provided in an oil pressure chamber 101 to be extendable and contractible, an oil supply hole 114, an oil supply space 102, and a plunger hole 124 that together form a continuous oil supply passage is formed in such a shape that an oil amount changes in accordance with a position of the plunger 120.

Abstract: Provided is a chain tensioner that can improve the degree of freedom in setting the oil supply position with a simple structure, can supply sufficient and necessary oil when restarted after a long time after the stop of oil supply, can entirely be made shorter and smaller, and can be produced easily with reduced cost. In a chain tensioner 100 in which a plunger 120 inserted in a plunger bore 111 of a tensioner body 110 is biased outward by biasing means 140 provided in an oil pressure chamber 101 to be extendable and contractible, an oil reservoir chamber 123 is formed on an outer side than a check valve 150 inside a plunger body 126, and a connection/adjustment groove 103 forming an oil supply space 102 is formed in an inner circumferential surface of the plunger bore 111.

Abstract: In a ring-type tensioner, a resilient ring that cooperates with external grooves formed on a plunger to restrict retracting movement of the plunger in a tensioner housing, is formed with manipulation parts that extend through a cut-out portion in the housing and have bulged portions that are spaced by gaps from opposed walls of the cut-out portions. A rod-shaped tool inserted into one of the gaps cooperates with the bulged portion and the wall on opposite sides of the gap to expand the ring. The manipulation parts can be formed with tool-holding portions.

Abstract: In a hydraulic tensioner, a check valve comprises a check ball disposed within a seat/retainer combination in which a ball seat and retainer are formed as a unit and connected by a bend. The check valve is mounted so that it can rotate within the tensioner housing about a center line, and formed so that its center of gravity is offset from the center line. The check valve unit therefore tends to assume a position in which its center of gravity is directly below the center line. Openings that allow flow of oil from the interior of the check valve unit to a hydraulic chamber in the tensioner are positioned so that, when the center of gravity of the check valve unit is directly below the center line, the check ball cannot block or restrict flow through the openings.

Abstract: A chain guide is provided in which durability is increased, weight can be reduced, material cost is reduced, the uniformity of resin orientation is improved, dimensional errors, errors in shape, internal strains, and defects are reduced, and bending rigidity such as rigidity against deflection and torsion is augmented with a simple configuration. The chain guide is provided with reinforcing ribs at a guide main body. The reinforcing ribs include first inclined reinforcing ribs and second inclined reinforcing ribs that cross each other. A zone in which the reinforcing ribs are not present is provided in the intermediate portion between two support porting.

Abstract: In a tensioner having a housing and a plunger protruding in an advancing direction from a plunger-accommodating hole formed in the housing. The plunger has a cylindrical outer wall for sliding contact with the wall of the plunger-accommodating hole, and a tapered the rear end wall. A small clearance between the cylindrical outer wall of the plunger and the wall of the plunger-accommodating hole allows the plunger to become inclined by a small amount, which increases as the plunger advances. The angle of the taper at a boundary where the end wall meets the cylindrical outer wall is substantially equal to the maximum inclination of the plunger when the plunger is in its fully advanced condition.

Abstract: A ratchet-type tensioner, comprising: a housing; a plunger supported by the housing for movement in opposite advancing and setback directions, the plunger having rack teeth provided thereon, and being arranged to advance with respect to the housing along the advancing direction for applying tension to a traveling transmission medium engaged with rotating members; and a ratchet mechanism capable of restricting the plunger from setting back due to a reaction force acting in a setback direction from the transmission medium; said ratchet mechanism comprising: a ratchet-receiving hole provided within the housing; a ratchet element slidable in the ratchet-receiving hole and movable in a sliding direction transverse to the advancing and setback directions; ratchet teeth on the ratchet element engageable with the rack teeth of the plunger; and a ratchet-biasing means for biasing the ratchet element in an engaging direction along the sliding direction so that the ratchet teeth engage with the rack teeth; said ratchet

Abstract: The chain guide mechanism includes a slack side guide, a tension side guide, and a link member that is capable of rotating about a predetermined rotary shaft provided so as to be fixed to an attachment subject. The link member includes a slack side pivot portion attached rotatably to the slack side guide, and the slack side pivot portion is disposed on an opposite side of the chain that is guided by the slack side guide to the predetermined rotary shaft, and in a lower position than the predetermined rotary shaft. The slack side guide is biased by its own weight toward a side of the chain that is guided by the slack side guide.

Abstract: Deaeration of the high pressure oil chamber of a hydraulic tensioner takes place though a helical orifice formed by opposed flanks of the threads of a threaded hole in the tensioner housing and the threads of a screw inserted into the hole. The opposed flanks are maintained in spaced relationship by a force exerted by a spring washer disposed between the head of the screw and a surface of the tensioner housing surrounding the opening of the threaded hole. The flank of the thread of the hole that forms part of the boundary of the helical orifice can have a concave curvature in order to increase the aperture of the air flow path. A groove in the surface surrounding the opening of the threaded hole prevents the washer from sealing off the flow of air. This groove is disposed with its exit end at a level above its entry end.

Abstract: The present invention provides a highly durable chain guide which is simply configured, easy to assemble, and low in material cost, and in which vibration and tilting are suppressed, enabling reductions in noise, wear, breakage, and so on. A guide shoe includes a plate housing portion which is formed on a rear surface side of a travel guiding portion, and into which a plate can be inserted from below, and in at least one location of an attachment portion or a tensioner contact portion, the plate housing portion constitutes a plate end holding portion formed to be capable of supporting an end portion of the plate from below such that the plate can be inserted therein from a direction other than from below.

Abstract: There is provided a ratchet-type tensioner whose spring stopping washer for seating a ratchet biasing spring is rigidly and readily assembled to a ratchet-receiving hole so as not to fall out of the ratchet-receiving hole and which reduces flapping noise and prevents seizure of the plunger by securely and stably operating a ratchet mechanism in operating an engine. The ratchet-type tensioner 100 is arranged so that the spring stopping washer has a C-ring anchored in the rear-end area of the ratchet-receiving hole by fitting in a diameter-reduced state and by enlarging its diameter within an anchoring circumferential groove of the ratchet-receiving hole and a spring stopping piece extended from the C-ring to a ring center area to seat the ratchet biasing spring.

Abstract: To provide a simple design chain tensioner that enables formation with fewer components and simplifies assembling process, and is capable of driving a chain stably, thereby reducing wear or occurrence of breakage and improve durability. The chain tensioner 100 includes a chain-drive guide shoe 130 pivotally supported on an arm 120 provided to a tensioner body 110. A bushing part 140 of the chain-drive guide shoe 130 includes a mating hole 141 to mate with a first pin portion 122 that extends from the distal end of the arm 120 to one lateral side, and a guide part 142 guided by a part of a second pin portion 123 that extends to the other lateral side, and a slit 143 wider than a portion of the arm 120 facing the chain-drive guide shoe 130 is provided between the mating hole 141 and the guide part 142.

Abstract: A transmission guide comprises a synthetic resin shoe supported by and integrally molded with a synthetic resin base by two-part molding. A guide length retaining mechanism, which can be formed by one or more protrusions on the back of the shoe and one or more cooperating recesses on the supporting surface of the base, retains the shoe against longitudinal movement relative to the base. A guide width retaining mechanism, which can be formed by projections on the edges of the shoe and cooperating holes formed in side walls extending from the supporting surface of the base, retains the shoe against widthwise movement relative to the base.

Abstract: The synthetic resin guide in accordance with the invention comprises an elongated synthetic resin shoe having a front surface for sliding contact with the transmission medium and a back surface opposite from the front surface and a plurality of engaging members disposed in longitudinally spaced relationship to one another. The guide also comprises an elongated synthetic resin base in contact with the back surface of the shoe and supporting the shoe, the base having a plurality of longitudinally spaced engaged portions each of which engages with one of the engaging members. One engaging member is fixed to the engaged portion with which it is engaged. The other engaging members are longitudinally movable relative to the engaged portions with which they are engaged. Thus, the guide allows longitudinal thermal expansion and contraction of the shoe relative to the base.

Abstract: A chain transmission is provided which is capable of reducing friction loss in the transmission of power without the risk of compromising the durability of a chain guide mechanism and the chain. The chain transmission includes a chain and a chain guide mechanism. The chain guide mechanism includes a first guide and a second guide having a smaller radius of curvature than that of the first guide. The plurality of plates include a first plate and a second plate. The first plate has a backside height set such that the first plate does not contact the first guide when the first plate is guided by the first guide and such that the first plate contacts the second guide when the first plate is guided by the second guide.

Abstract: A chain guide is provided in which durability is increased, weight can be reduced, material cost is reduced, the uniformity of resin orientation is improved, dimensional errors, errors in shape, internal strains, and defects are reduced, and bending rigidity such as rigidity against deflection and torsion is augmented with a simple configuration. The chain guide is provided with reinforcing ribs at a guide main body. The reinforcing ribs include first inclined reinforcing ribs and second inclined reinforcing ribs that cross each other. A zone in which the reinforcing ribs are not present is provided in the intermediate portion between two support porting.

Abstract: The occupation space of a chain inside an engine room can be reduced, while the necessary strength, rigidity, and durability are maintained, the sheet thickness can be decreased, the number of production steps and material waste can be reduced, stress concentration and strains during bending and fixing can be reduced, load offset during fixing and loosening of bolts or the like can be prevented, the increase in vibrations and noise during the use can be prevented, the maintenance operation load can be reduced, and utility can be increased with a simple configuration. A chain guide is provided with a base member supporting a guide shoe. The base member has a base mounting portion and base wall portions formed to sandwich the guide shoe from both sides in a width direction. The guide shoe has a guide shoe mounting portion at a position apart from the base mounting portion in the chain running direction.